East Coast quake causes major cell service disruptions

NEW YORK (CNNMoney) -- Cell service along the East Coast was spotty following a Virginia-based earthquake that was felt as far away as New England.

There were no reports of downed cell towers or wires, but mobile providers said that millions of people tried to make cell phone calls at the same time, resulting in overwhelmed cellular relay stations.

Verizon Wireless reported network congestion for some customers in the Eastern United States for about 20 minutes following the earthquake, which hit just before 2 p.m. ET. The quake measured 5.8 on the Richter scale.

"We are seeing no reports of damage to our wireless network," said Verizon (VZ, Fortune 500) spokesman Jeff Nelson. "Everything returned to normal quickly once the tremors ended. We'll continue to monitor the network."

Nelson said the mobile company's infrastructure was built to withstand earthquakes of such a magnitude. Verizon's super-switching centers in Florida, for instance, are designed to withstand a Category 5 hurricane.

AT&T (T, Fortune 500) spokesman Mark Siegel also said that there was no infrastructure damage, but the network continues to experience "heavy call volumes." He said customers who could not connect might try to communicate by text messages, which require far less bandwidth than phone calls.

Sprint (S, Fortune 500) said via a spokeswoman that its network was not impacted by the earthquake, but a "temporary mass calling event" impacted some customers' ability to place and receive calls. The company said such a high volume of calls was typical following similar incidents, and Sprint advised customers to be patient or send texts instead of placing calls.

A T-Mobile spokesman also confirmed that the network was experiencing higher call volumes in all earthquake-affected areas.

Cell service disruptions occur during periods of heavy call volumes because of a bottle-necking factor: Like a highway that gets congested during rush hour, cellular infrastructure is not designed to handle the amount of calling traffic that occurs during emergency situations.

"We don't engineer pipes to handle every call at the same time," said Akshay Sharma, wireless infrastructure consultant at Gartner. "Even though we have redundancy built in, guess what, most of that feeds into the same pipes."

Calls are typically routed from relay station to relay station via the shortest distance between the two points of a call. But if one switching station gets overwhelmed, calls then need to be relayed around that station, and delays occur.

Cell phone calls weren't the only communication technology peaking after the earthquake. Internet traffic also spiked right around 2:15 p.m. ET, according to content delivery network Akamai (AKAM).

The tremors sent people racing to the Internet, resulting in a peak of 3.3 million page views per second on the news websites supported and tracked by Akamai -- 25% above normal for a Tuesday afternoon, but still about 800,000 page views short of the spike that occurred on May 1 when President Obama announced Osama bin Laden.